001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.camel.processor; 018 019import java.util.Comparator; 020import java.util.Set; 021import java.util.TreeSet; 022 023import org.apache.camel.CamelContext; 024import org.apache.camel.Exchange; 025import org.apache.camel.Expression; 026import org.apache.camel.Processor; 027import org.apache.camel.Traceable; 028import org.apache.camel.util.ExpressionComparator; 029 030/** 031 * An implementation of the <a href="http://camel.apache.org/resequencer.html">Resequencer</a> 032 * which can reorder messages within a batch. 033 * 034 * @version 035 */ 036@SuppressWarnings("deprecation") 037public class Resequencer extends BatchProcessor implements Traceable { 038 039 // TODO: Rework to avoid using BatchProcessor 040 041 public Resequencer(CamelContext camelContext, Processor processor, Expression expression) { 042 this(camelContext, processor, createSet(expression, false, false), expression); 043 } 044 045 public Resequencer(CamelContext camelContext, Processor processor, Expression expression, 046 boolean allowDuplicates, boolean reverse) { 047 this(camelContext, processor, createSet(expression, allowDuplicates, reverse), expression); 048 } 049 050 public Resequencer(CamelContext camelContext, Processor processor, Set<Exchange> collection, Expression expression) { 051 super(camelContext, processor, collection, expression); 052 } 053 054 @Override 055 public String toString() { 056 return "Resequencer[to: " + getProcessor() + "]"; 057 } 058 059 public String getTraceLabel() { 060 return "resequencer"; 061 } 062 063 // Implementation methods 064 //------------------------------------------------------------------------- 065 066 protected static Set<Exchange> createSet(Expression expression, boolean allowDuplicates, boolean reverse) { 067 return createSet(new ExpressionComparator(expression), allowDuplicates, reverse); 068 } 069 070 protected static Set<Exchange> createSet(final Comparator<? super Exchange> comparator, boolean allowDuplicates, boolean reverse) { 071 Comparator<? super Exchange> answer = comparator; 072 073 if (reverse) { 074 answer = new Comparator<Exchange>() { 075 public int compare(Exchange o1, Exchange o2) { 076 int answer = comparator.compare(o1, o2); 077 // reverse it 078 return answer * -1; 079 } 080 }; 081 } 082 083 // if we allow duplicates then we need to cater for that in the comparator 084 final Comparator<? super Exchange> forAllowDuplicates = answer; 085 if (allowDuplicates) { 086 answer = new Comparator<Exchange>() { 087 public int compare(Exchange o1, Exchange o2) { 088 int answer = forAllowDuplicates.compare(o1, o2); 089 if (answer == 0) { 090 // they are equal but we should allow duplicates so say that o2 is higher 091 // so it will come next 092 return 1; 093 } 094 return answer; 095 } 096 }; 097 } 098 099 return new TreeSet<Exchange>(answer); 100 } 101 102}